No you do not need to know C before C++. Visual C++ is Microsoft's little varient of C++, which a lot of people use, though the difference is not huge. Learning C++ is fairly easy as far as the sytax and such go, the libraries are what take time, so I would make sure whatever book you get includes the Standard Libraries. :)

I have never liked the Dummie books, but others do, it is a matter of personal preference. The book I use is C++: The Complete Reference, 4th Edition. Although as a first language I would recommend Java, but C++ is probably more useful. :)